L'Wren Scott committed suicide by hanging

In this photo taken on May 19, 2010 British singer of "The Rolling Stones", Mick Jagger and US stylist L''''Wren Scott arrive for the screening of "Stones in Exil" . (AFP)

Fashion designer L'Wren Scott, who was found dead in her upscale high-rise Manhattan apartment on Monday, died by hanging, the New York City medical examiner's office said.

Scott, who was the girlfriend of Rolling Stones lead singer Mick Jagger, committed suicide, said Julie Bolcer, the spokeswoman for the medical examiner's office.

Police had been treating the death of Scott, 49, as an apparent suicide after finding the designer's body with a scarf around her neck.

Her sleek, sexy clothes were worn by Hollywood stars such as Nicole Kidman and First Lady Michelle Obama.

Funeral details had not yet been confirmed, according to her publicist.

In a posting on his official website, Jagger spoke of his distress and sorrow about her tragic death.

"I am still struggling to understand how my lover and best friend could end her life in this tragic way," he said in the post on mickjagger.com. "She had great presence and her talent was much admired, not least by me."

Despite Scott's success on the runway, accounts filed in London last October showed that her company, LS Fashion Ltd, had a loss of 4.3 million euros ($5.99 million) in 2012, up from 3.0 million euros the previous year.